Just looking for a little clarification on water heaters located in homes where subject to damaging the surround finish.

P504.6 states: #2 states it shall discharge through an air gap in the same room. The last choice in #5 states it can be piped to the exterior which contradicts #2.

P504.7 states: heaters located where they will cause damage must be installed in a pan. The pan must be of sufficient size to contain all drippings / condensate from the heater. (Good luck with that...never seen one.) Sarcasm is mine. The drain can be piped to exterior or floor drain.

I just witnessed someone pay a plumber today $1200 to install Taco auto shut-off valves on 2 heaters in a duplex to try and comply with the plumbing code on a 4 point I did for them. I see no exemption to P504.7 that would allow this.

Then In its infinite wisdom the code does away with all of the mostly sensible previous requirements when in P504.7.2 states where no pan was previously required........none shell be required for a heater replacement. I could hear the water damage / remodeling contractors cheering in my head. Evidently their lobbyist was worth every penny!

First things first ... how do you get to the FBC-Plumbing from the FBC-Existing Buildings? (You start at the FBC-Existing Buildings for existing buildings.)

That said, if you start at the FBC-Existing Buildings, you ... stumble into a mis-mash of left out code to specifically ... take you anywhere specific ...

From the FBC-Existing Buildings (underlining is mine) - (definitions) - - [A]REPAIR. The reconstruction or renewal of any part of an existing building for the purpose of its maintenance or to correct damage.

Replacing a water heater would be considered a "repair" by the definition, however, unlike replacing water closets, replacing a water heater is not specifically ... specifically ... listed.

However ...

From the FBC-Existing Buildings (underlining is mine) - 502.1 Scope. - - Repairs, as defined in Chapter 2, include the patching or restoration or replacement of damaged materials, elements, equipment or fixtures for the purpose of maintaining such components in good or sound condition with respect to existing loads or performance requirements.

Thus, from the above, we can get to 'replacement of a water heater' in the FBC-Existing Buildings, and that it is a "repair".

(continuing from FBC-EB) - 601.1 Scope. - - Repairs as described in Section 502 shall comply with the requirements of this chapter and with the provisions of Section 706. Repairs to historic buildings need only comply with Chapter 12.

(Section 706 is for "existing roofing".)

The following is key to most things in the FBC-Existing Buildings: (bold and underlining are mine) - 601.2 Conformance. - - The work shall not make the building less conforming than it was before the repair was undertaken.

I.e., if a drain pan was not present before, not installing a drain pan when the water heater is replaced is not make it "less conforming that it was before".

- Section 101.1 Title. - - These regulations shall be known as the Florida Building Code, Existing Building, hereinafter referred to as “this code.” In addition to the provisions of this chapter, [u]the provisions of Chapter 1, Florida Building Code, Building, shall govern the administration and enforcement of this code[/u].

That gets us to Chapter 1 of the full Administrative sections of the code, and Chapter 1 is the same for both FBC-Building, and FBC-Residential ... which can lead to the FBC-Residential plumbing chapters for water heater replacement in one- and two-family dwellings and townhouses - which is:

- CHAPTER 28 - - WATER HEATERS

and

- SECTION P2804 - - RELIEF VALVES

and

- P2801.6.1 Pan size and drain. - - The pan shall be not less than 1 1/2 inches (38 mm) deep and shall be of sufficient size and shape to receive dripping or condensate from the tank or water heater. The pan shall be drained by an indirect waste pipe of not less than 3/4 inch (19 mm) diameter. Piping for safety pan drains shall be of those materials indicated in Table P2906.5. Where a pan drain was not previously installed, a pan drain shall not be required for a replacement water heater installation.

(Keep this from above in mind "The work shall not make the building less conforming than it was before the repair was undertaken")

Also, think logically - if the water heater was in the center area of a house ... how could you install a drain for the pan (and a pan without a drain is useless)?

(back to Relief Valves and discharge lines) - P2804.6.1 Requirements for discharge pipe. - - The discharge piping serving a pressure-relief valve, temperature relief valve or combination valve shall: - - - 1. Not be directly connected to the drainage system. - - - 2. Discharge through an air gap located in the same room as the water heater. - - - 3. Not be smaller than the diameter of the outlet of the valve served and shall discharge full size to the air gap. - - - 4. Serve a single relief device and shall not connect to piping serving any other relief device or equipment. - - - 5. Discharge to the floor, to the pan serving the water heater or storage tank, to a waste receptor or to the outdoors. - - - 6. Discharge in a manner that does not cause personal injury or structural damage. - - - 7. Discharge to a termination point that is readily observable by the building occupants. - - - 8. Not be trapped. - - - 9. Be installed to flow by gravity. - - - 10. Terminate not more than 6 inches (152 mm) and not less than two times the discharge pipe diameter above the floor or waste receptor flood level rim. - - - 11. Not have a threaded connection at the end of the piping. - - - 12. Not have valves or tee fittings. - - - 13. Be constructed of those materials indicated in Section P2906.5 or materials tested, rated and approved for such use in accordance with ASME A112.4.1. - - - 14. Be one nominal size larger than the size of the relief-valve outlet, where the relief-valve discharge piping is constructed of PEX or PE-RT tubing. The outlet end of such tubing shall be fastened in place.

Read #2 and #5 again - they are not contradictory: - 2 requires an air gap in the same room or space as the water heater - 5 says that the discharge from the air gap may go to ... (gives choices)

Did they install the senor on the floor under/next to the water heater when they installed the auto shut off valve?

Logic and common sense come into play here: - 1a) the purpose of the sensor is to detect a leak - 1b) the purpose of the auto shut off valve is to shut the water off if a leak is detected and not damage anything inside - 2) the purpose of the pan and drain is to allow leaking water to drain outside and not damage anything inside - doesn't 1a and 1b solve the problem as well as 2? - 3) and ... Keep this from above in mind "The work shall not make the building less conforming than it was before the repair was undertaken" - 4) doesn't 3) allow 2), and isn't that actually better than "Where a pan drain was not previously installed, a pan drain shall not be required for a replacement water heater installation."?

OK you got me about using the plumbing code as opposed to the Existing code....but they all say the same thing.

I think logically it makes no sense to give a complete pass on not installing a pan and drain if possible.......your just enabling substandard work and I can hear you saying The building codes are the MINIMUM requirements. I think the codes should encourage better work if possible.

The pan is useless unless piped to the exterior as even if a shutoff valve is installed nobody installs 30-50 gallon pans to contain leakage from a full heater. Yes I get the trade off for space in that its not likely to completely empty with in a day or two as most leaks are small for a long time and hopefully the homeowner notices before the flood.

Thankfully most builders have gotten away from installing heaters in the center of a house but condo buildings install drained pans from the center of a living unit all the time it just takes a little planing and thought.

Installing an air gap....and then some kind of funnel under the pipe to continue to the exterior is unrealistic....talk about a water / leakage / damage issue. I can't even understand why such an option would be considered. The issue here is back siphoning correct? The TPR valve only opens when its reaches its rated temp / pressure and if not trapped as required it seems to me you have a better chance of seeing Jesus then of water back siphoning into your water heater. Do you know why or what problem this air gap requirement was supposed to fix? Forgive me as right now I have too much time on my hands.

In this particular setup the heaters were installed in pans in laundry rooms up on a wall hung shelf. The exterior wall was 8" away with plenty of elevation to install a drain line to the exterior. The plumber capped the drain outlets and installed the sensors down in the pans just like an air handler in the attic . Now I can't blame the plumber for making a nice buck on a willing participant but the fact is that an unlikely discharge from the TPR valve would not be handled well by this shut-off setup nor a leak that goes unnoticed by the homeowners.

So if I understand your comments something like this would be allowed because its making the best of an almost impossible situation?

bigdog wrote:So if I understand your comments something like this would be allowed because its making the best of an almost impossible situation?

Correct.

Additionally, when a leak is detected and the auto shut off valve shuts off the water to the tank, pressure is lost to the water heater, the first time someone goes to use hot water ... blip ... and the residual pressure is released (provided the leak didn't already bleed off the residual pressure) ... No residual pressure in the tank and the leak is greatly reduced to that of gravity.

And the person not getting hot water knows 'something isn't right' and likely calls a plumber.

Thus, not having a 40 gallon pan is likely not an issue - except maybe in a vacant house/unit, however even then you are only talking about 40 gallons ... versus a leaking water supply pipe under pressure.